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For volatile organic compounds (VOCs) to be released from the plant cell into the atmosphere, they have to cross the plasma membrane, the cell wall, and the cuticle. However, how these hydrophobic compounds cross the hydrophilic cell wall is largely unknown. Using biochemical and reverse-genetic approaches combined with mathematical simulation, we show that cell-wall localized non-specific lipid transfer proteins (nsLTPs) facilitate VOC emission. Out of three highly expressed nsLTPs in petunia petals, which emit high levels of phenylpropanoid/benzenoid compounds, only PhnsLTP3 contributes to the VOC export across the cell wall to the cuticle. A decrease in PhnsLTP3 expression reduces volatile emission and leads to VOC redistribution with less VOCs reaching the cuticle without affecting their total pools. This intracellular build-up of VOCs lowers their biosynthesis by feedback downregulation of phenylalanine precursor supply to prevent self-intoxication. Overall, these results demonstrate that nsLTPs are intrinsic members of the VOC emission network, which facilitate VOC diffusion across the cell wall.
Assuntos
Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/metabolismo , Difusão , Fenilalanina , Parede Celular/metabolismo , LipídeosRESUMO
Numerous secondary metabolites from plants are important for their medicinal, nutraceutical or sensory properties. Recently, significant progress has been made in the identification of the genes and enzymes of plant secondary metabolic pathways. Hence, there is interest in using synthetic biology to enhance the production of targeted valuable metabolites in plants. In this article, we examine the contribution that metabolic flux analysis will have on informing the rational selection of metabolic engineering targets as well as analysis of carbon and energy efficiency. Compared to microbes, plants have more complex tissue, cellular and subcellular organization, making precise metabolite concentration measurements more challenging. We review different techniques involved in quantifying flux and provide examples illustrating the application of the techniques. For linear and branched pathways that lead to end products with low turnover, flux quantification is straightforward and doesn't require isotopic labeling. However, for metabolites synthesized via parallel pathways, there is a requirement for isotopic labeling experiments. If the fed isotopically labeled carbons don't scramble, one needs to apply transient label balancing methods. In the transient case, it is also necessary to measure metabolite concentrations. While flux analysis is not able to directly identify mechanisms of regulation, it is a powerful tool to examine flux distribution at key metabolic nodes in intermediary metabolism, detect flux to wasteful side pathways, and show how parallel pathways handle flux in wild-type and engineered plants under a variety of physiological conditions.
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Heart failure (HF) is a chronic, progressive disease that substantially decreases patients' quality of life. Few studies have compared quality of life and its related factors across genders in patients with HF. To explore gender differences in quality of life and related factors among adult patients with HF. A comparative study was conducted with 245 HF patients recruited from a medical center and a regional teaching hospital in Taiwan from February 2009 to February 2011. Descriptive and inferential statistics were used, including stepwise multiple regressions. The mean quality of life scores of males were significantly higher than those of females (87.78 ± 13.99 vs. 84.49 ± 11.85). The factors significantly related to quality of life for the male HF patients, in descending order of strength of association were depressive symptoms, physical symptoms, and monthly family income-less than USD 1,000; for the females, the significantly related factors were physical symptoms, depressive symptoms, and monthly family income-less than USD 1,000. The amount variance for which quality of life accounted for male and female HF patients was similar (60% vs. 64%). The results could be used for health professionals to provide more appropriate assessments and care according to gender in the future.
Assuntos
Depressão/epidemiologia , Insuficiência Cardíaca/psicologia , Qualidade de Vida , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Inquéritos e Questionários , Taiwan/epidemiologiaRESUMO
Rogers' model treats people and the environment as pan-space energy fields that integrate with one another and exchange energies. The nurse model is an abstract system concept that emphasizes totality, experiences, existence and correlates with the continuous nursing model emphasized by the current health nursing system. Rogers' model offers an abstract philosophical framework to explain "whole person-environment field phenomenalism." This article discusses and critiques the application of Rogers' theory in nursing practice. The author hopes that it will help nurses better understand Rogers' theory and his central concept in order to better apply them in nursing practice.
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Pesquisa em Enfermagem , Teoria de Enfermagem , Humanos , Modelos de EnfermagemRESUMO
BACKGROUND: Heart failure is a chronic and exacerbating disease, which often significantly decreases patient quality of life (QOL). Treatments continue to focus on alleviating the physical symptoms of this disease, and data on QOL factors are limited. PURPOSE: The purpose of this study was to explore QOL and associated factors in patients with heart failure. METHODS: A cross-sectional and correlational research design was conducted using the Kansas City Cardiomyopathy Questionnaire, Beck Depression Inventory-II, and the World Health Organization Quality of Life Assessment. A convenience sample of 200 patients aged 20 years old or above and diagnosed with heart failure were recruited from one medical center and one regional teaching hospital in southern Taiwan. Data were analyzed using SPSS 14.0 software. RESULTS: Results found (1) participants had an average QOL index score of 63.0 (moderate); (2) significant differences in QOL scores for the variables of marriage, occupation type, monthly family income, concomitant diabetes/hypertension, number of complications, and treatment type; (3) participants had an average index score for symptoms of 54.1 (moderate) that was significantly correlated with QOL; (4) a majority of participants were classified in NYHA Class II, mean score of depression was 9.13±6.25 (normal), and functional status and depression were significantly related to QOL; and (5) 59.3% of QOL variance was explained by depression, symptoms and family income per month. CONCLUSIONS: This study may help health professionals to understand relationships among symptoms, functional status, depression and QOL in heart failure patients. It may also provide healthcare professionals evidence-based data necessary to further improve symptoms, functional status and depression in heart failure patients, and thus significantly improve QOL in patients with heart failure.